JSP JSTL Functions

JSP Function JSTL

The JSP Standard Tag Library (JSTL) adds essential features to JSP that enable JSP programming without the need for embedded Java code.

It is a collection of standard JSP tags that perform several common tasks.

This frees us from having to develop custom tags for these tasks, or from using a mix of tags from several organizations to do our work.

The Function JSTL contains a number of string manipulation functions.
These include functions for splitting and concatenating strings, returning substrings, determining whether a string contains a
specified substring, and many others.

Before using the Function JSTL, the following directive needs to be added to the JSP page:

This file starts with the normal xml tag for a XML file and
the root tag for the deployment descriptor is web-app. Every ting
inside the last tag is to tell the server about our application,
which in this case is a JSP file.

With a servlet tag we give the JSP file a servlet name,
which is used in the servlet-mapping tag to specify a url
for the JSP file.

In this way we can have many urls for the same JSP file.

If no session-timeout (the server ends the service
of the application after this time) is given a standard timeout for the server is used
as timeout for the application.

The welcome-file tag specifies the startup for our application,
which in this case and our application is the welcome file with url FunctionJSP.
Reorganize the welcome-file-list to what is shown above.

Creating Web-server Deployment descriptor.

The context-root (in example /FunctionJSTL) for the application
will in most cases be specified by a server vendor deployment descriptor.